Planoffrafih co



J. C. KOPF.

JACK.

APPLICATION FILED MAY 15. I919.

1,317,878. I Patented 0%. 7,1919.

4 SHEETS-SHEET I.

A TjTORNE Y.

Tm: coummn I'LANOUIAPII 00., WASHINGTON, I} c.

J. C. KOPF.

JACK.

APPLICATION FILED MAY l5. l9l9.

' 1,317,878. I Patented Oct. 7,1919.

4 SHEETS-SHEET 2- W m 55 E ATTORNEY.

J. C. KOPF.

JACK.

APPLICATION FILED MAY 15. 1919. 1,317,878. Patented Oct. 7,1919.

4 SHEETS-SHEET 3- 1-7 5 17- 30 -I 15 I 15 7 I 7 '15, l 1/ 14 l4 6 I J 12 A TTORNE Y.

1. c. KOPF;

JACK.

APPLICATION FILED Mans. 1919.

4 SHEETS-SHEET 4.

1,317,878. Patented Oct. 7,1919.

A TTORNE Y.

'n m cownsm any damp" co., WASHINOAON. o. c.

UNTED sr 1 JOHN C. KorF,-or BELLEVUE BOROUGH, PENNSYLVANIA,=ASSIGNOR TO THE DUFF MANUFACTURING COMPANY, OF :errrssuacrn, PENNSYLVANIA, A CORPORATION OF PENNSYLVANIA.

' (TACK.

I Specification Of Letters Patent.

Patented Oct.- 7, 1919.

Application filed May 15, 1919. Serial No. 297,237,

To all whom it may Concern Be it known that I, JOHN C. Korr, a citizen of the United States-and resident of the borough of Bellevue, in the County of Allegheny and State of Pennsylvania, have i11- vented a new and useful Jack, of which the following is a specification. v

The invention relates to pushing and pulling devices, and particularly to jacks, and specifically is an improvement upon that type of jack long known wherein a double rack-bar, that is to say one provided with rack teeth upon both sides, is' rojlled upward between a pairof simultaneously acting pinions, instead of being slid up by a single pinion and set of rack teeth against friction. The object is to provide a jack or similar device combining the advantage of this principle of Operation for moving heavy loads, with a novel and improved self-locking driving means whereby high; mechanical efficiency, great strength, and simplicity of manufacture are obtained. Worm gearings have been Well known as self-locking powerdriving means for jacks, but the present jack-operating means differs essentially fromaworm gearing, in acting radially instead of axially, in exhibiting linecontact instead of facecontact, and in-having a greater angle of efficiency and less-friction.

, A general object isto provide a simple, strong, compact, serviceable, and easily manufactured jack or the like. 1 p a In theaccompanying drawings forming a part hereof: I P

4 .Figurel is a sectional side elevation of a jack embodyingthe invention; V

Fig. 2 is an elevation at right anglesto Fig. 1 looking" into the screw box, the cover the double rack, pinionsand buttress-gears; and

Fig. 6 is a view of the inner part of the jack-handle, mainly in section.

The jack shown in the drawings has a frame or housing, in the form of an upright stand 1 with expanded base 2. Throughout the height of the housing is a rack-guide channel In this guide is a rack 4;, having rack-teeth 5 upon opposite sides. The faces ofthe'bar are channeled as seen in Fig. 3, the inner channel being designated 6. p

At opposite sides of the rack-bar, in the upper back part of the stand are pinion chambers 7, behind which are rear or outer bearing bosses '8 in the wall. At the opposite or forward part ofthe stand is a gearbox 9, having a cover 10, secured by screws 11 Horizontal tubular inner bearing bosses 12 are formed in the interior of the housing, in alinelnent with the outer bearings 8, the internal diameter of the bosses 12 however being greater. Bushings 13 are seated in the bosses '12, and pinion shafts 14 are journaled in said bushings and in the rear bearings 8. Pinions 15 011 the shafts between the journal portions. 16 and 17 mesh with the teeth of the rack. Inassembli-ng, the shafts with the pinions thereon are intro.

serted through thebosses 12 from the front of the gearbox, the interior of .said bosses being made a little larger than the pinions to permit them to pass. Thereafter the bushings are introduced into their seats. As shown in Fig. 5, the teeth of the pinions are bent forward, thus avoidingundercut ting and securing a good rolling contact.

' The forward portions of. the shafts let are made polygonal; and upon them within the gear-box are gears 18, These gears are made with straight buttress teeth, that is to say teeth having substantially perpendicular or radial working faces 19, extending". in the transverse directionparallel with :the axis, and sloping backs 20, each tooth being thus approximately .a right angled triangle. An operating shaft 21 rests in channel bearings 22 in the bottom of the gear-box, formed part in the body and part in the cover; and

njthis shaft,-projecting between} the conthread. This spiral working face is of a length'to engage a series of teeth, in this instance three, at a time, and in order to follow the curve of the gear it possesses also a lesser pitch in the longitudinal direction. The spiral pitch causes driving pressure perpendicular to the operating shaft 21, the helical pitch enabling the working face 2% to pursue the teeth of the gear as they travel upward in their curved path, so that the driving pressure is constantly applied at a plurality of points. Both the predominating spiral and the attendant helical pitch are constantly varying, as is also the working face angle, the variation being such as to enable the parts to mesh in the manner inclidated. The contact between the working face of the pinion and the working face of each gear tooth in action is a single line, thereby reducing friction. The triangular form of the teeth 19 of the oppositely rotatable gears gives strength to these parts; and in the driving pinion 23 the body itself resists shear. An advantage of the construction is that the two sides of the double conical spiral buttress pinion can be cut at one operation, which is both economical and in sures perfect synchronism, the latter being of primary importance in a. jack of this type, because if the two sides of the mechanism are not in harmony the work will fall mainly on one of them. On the other hand, in

' manufacturing the frame and working parts and assembling them, it is not necessary toobserve great accuracy as to centers, as the gearing will work efficiently with considerable variation in this respect, because of the line contact. The double pinion is preferably made as an integral member, but it might manifestly be split or made in two halves secured to the operating shaft, though less desirably. In operation the periphery of the spiral pinion passes within the channel 6 of the rack-bar.

The top of the rack-bar bears a head 25, preferably formed of a separate piece having a, hole, through which a stud projection 26 of the bar is passed and riveted over. From the head there depends rigidly a toelift bar 27 having a slide block 28 formed on its lower portion to operate in an exterital channeled slideway constituted by bearing surfaces 29 upon the outer face of the wall and vertical ribs 30 projecting therefrom. The sides of the toe-lift bar are channeled as indicated at 31, and its outer edge is provided with a series of customary holding notches 32. The adjustable toe-lift 33 is of known kind. having lugs 34 embracing the channeled sides of the bar and a dog extremity 35to engage the holding notches. Heretofore difficulty has been experienced from the toe-lift becoming dislodged. To overcome this means are hereby provided for causing thetoe-lift to seek the notches, such means being preferably embodied as a counterweight 36 on the bracket web 37 adjoining the platform 38 and limb 3,9 of the toe lift. V.

A rocker i0 is journaled on the projecting end of the operating shaft 21, to which, between the cheeks of the rocker, is fixed a ratchet wheel 41 having symmetrical teeth. The rocker has a handle-socket 42 formed therewith as usual, to receive the handle 4&3. A double reversible pawl =14; is pivoted at as between the sides of the rocker, at the base of the handle socket, where its back 46 can be encountered by an offset projection 47 on the end of the handle, so that according as the handle is thrust into the socket with said projection at one side or the other of a pin 48 the pawl is shifted to one working position or the other. At one end, the pawl has two spring-seat notches 4:9, separated by a protuberance 50, to receive the rounded end of a blade spring- 51 in the respective positions of the pawl. A simple mode of mounting the spring, permitting of ready replacement, is secured by straining the spring beneath a bridge 52 on the handle socket, and by seating its rear'end over a low stud 53, which passes through a hole in the spring.

In the lifting or working operation, the double spiralpinion 23 exerts lifting pres- 95 sure upon theteeth of the buttress gears 18, and the latter in turn cause the pinions 15 to lift the rack-bar 4 from opposite sides. Thus, the action as a whole is at right-angles to the operating shaft, and the reaction is downward, being taken by the lower sides of the shaft bearings, with no tendency for endwise displacement.

What I claim as new is: p 1. A. jack, comprising a stand, a double rack-bar therein bearing a head, andpinions meshing the rack-bar at opposite sides, and in combination therewith, a pair of buttress gears connected with the rack-pinions, a transverse operating shaft and a double conical spiral buttress pinion on said shaft projecting in meshing engagement between said buttress gears and acting thereon at right angles to the operating shaft, the but- 7 tress gears having their teeth reversedand facing toward the spiral pinion between them. j V

2. A jack, comprising a stand, a double rack-bartherein bearing a head, and pinions meshing the rack-bar at opposite sides, and in combination therewith, a pair of buttress gears connected with the rack-pinions, a transverse shaft. a double spiral pinion on said shaft meshing between said gears, the working faces of said spiral pinion having a helical pitch less than the spiral pitch and meshing with series of teeth on the con verging arcs of the gears and acting thereon at right angles to. the shaft, the buttress gears having their teeth reversed and facing toward the spiral pinion between them, and means for operating said pinion.

3. In a device of the dharacter described, the combination with a frame, a double rack-bar movable relatively thereto, and pinions meshing the rack-bar at opposite sides journaled in the frame, of a pair of buttress gears connected with the rackpinions, a transverse operating shaft and a double conical spinal pinion on said shaft projecting in meshing engagement between said buttress gears and acting thereon at right angles to the operating shaft, the buttress gears having their teeth reversed and facing toward the spiral pinion between them.

4. A device of the character described,

7 comprising a double rack-bar, pinions meshing therewith at opposite sides, shafts bearing said pinions, a housing chambered to accommo'diate the rack and pinions and having outer bearing for said shafts and inner bearings therefor of a size to permit the p-inions to pass, bushings in said inner bearings, buttress gears on said shafts in front of the bushings, a transverse operating shaft and a double conical spiral buttress pinion on said shaft meshing between said buttress gears and acting thereon at right angles to the operating shaft, the buttress gears having their teeth reversed and facing toward the spiral pinion between them.

5. In a device of the character described, the combination of a frame, a rack-bar movable relatively thereto having rack-teeth upon opposite sides and a channel in its face, pinions meshing the teeth upon opposite sides of the bar, buttress gears connected with the rack-pinions, a transverse operating shaft and a double conical spiral buttress pinion projecting in meshing engagement between the buttress gears and positioned to projectlaterally into the channel of the rack-bar, said pinion acting upon the buttress gears at right angles to the operating shaft, the teeth on the gears being reversed and facing the spiral pinion between them.

JOHN C. KOPF.

Copies of this patent may be obtained for five cents each, by addressing the Commissioner of Patents, Washington, D. G. 

